Signal apparatus



y W37. c. E. BEACH Re. 29,449

SIGNAL APPARATUS Original Filed Nov. 5, 1931 8 Sheets-Sheet l 65' O IL 2 1 fl Z 4/ 1 INVENTOR 6 ATTORNEY July 29, 193?; c, BEACH Re. 20,449

SIGNAL APPARATUS Original Filed Nov. 5, 1931 8 Sheets-Sheet 2 INVENTOR ATTORNEY I y 20, 1937- c. E. BEACH SIGNAL APPARATUS Original Filed Nov. 5, 1951 Sheets-:Sheet 5 INVENTOR ATTORNEY Julyzii, 1937. Q BEACH Re. 20,449

SIGNAL APPARATUS Original Filed Nov. 5, 1931 8 Sheets-Sheet 4 July 20, 1937. c BEACH 1 Re. 20, 449

S IGNAL APPARATUS Original Filed Nov. 5, 1931 '8 Sheets-Sheet 5 Jul 20, 1937, -c. E. BEACH SIGNAL APPARATUS- Original Filed Nov. 5, 1931 8 Sheets-Sheet 6 July20,1937. E BEACH Re. 20,449

' SIGNAL APPARATUS Driginal Filed Nov. 5, 1951 8 Sheets-Shet 7 .July 20, 1937. c. E. BEACH SIGNAL APPARATUS Original Filed Nov. 5, 193; a Sheets-Sheet 8 germ/ 07 hrerzce .fleaq 0 7 d 2 w y 1 Reissued July 20, 1937 UNITED STATES PATENT OFFICE SIGNAL APPARATUS Mass, a corporation of Massachusetts Original No. 1,999,859, dated April 30, 1935, Se-

rial No. 573,150, November 5, 1931.

Applicalion for reissue April 22, 1937, Serial No. 138,480

48 Claims.

This invention relates to signal formulating or transmitting mechanisms and systems, and more particularly to improvements in apparatus of the type comprising a series of widely separated signal transmitters connected to a central signal receiving station, for example, to apparatus such as a circuit including a plurality of fire alarm boxes or similar signaltransmitters connected to a central signal receiving station. I'he invention particularly affords improvements in successive non-interfering signal transmitters as commonly employed for such purposes.

Apparatus of the class to which this invention relates is depended upon to avoid serious property loss and even in many cases loss of life itself; accordingly, it is a primary object of the present invention to afford an especially dependable signaling apparatus and particularly to provide a device of this character which is operable under a wider variety of adverse conditions than ias been the case with any device of the general character which has been heretofore provided. Particularly the present invention provides a signaling device adapted to transmit signals over an emergency line or common return, such as a ground, if the regular circuit becomes faulty, While avoiding the closing of such an emergency circuit when the normal operating circuit remains properly conditioned. This ingo vention also affords a signaling device arranged to operate when serially associated with similar devices without interference between such devices even if they are simultaneously or substantially simultaneously actuated. Thus the 3,; present invention affords an improved type of signaling device of the perfect non-interfering type, as Well as a. device having an improved emergency switch or ground wire return arrangement, and this invention particularly provides in for the convenient association of both of theseadvantageous arrangements in a single signaling apparatus, thereby afiording a wide range of utility and dependability, even under serious adverse conditions.

45 This invention may be utilized in connection with systems for fire alarm or signaling service in which the circuits comprise metallic loops serially routed-through a; considerable number of code signal transmitting call or alarm boxes, and

so in which, at a centralpoint orstation, the loop ends are connected through indicating or control devices to a suitable current source. Such current sources are generally referred to as the central station battery and may be normally si free from ground connections so that the systerm may normally function as a full metallic or loop circuit. Such systems ordinarily include facilities for suitably associating a ground connection with the central station battery, which facilities may be made available, either manually or otherwise, whenever certain irregularities or faults may develop or threaten in the circuits or apparatus, so that intended signaling. response at the central station may result from closing and breaking of a connection between one or the other or both portions of the signal circuit and the ground.

Signal formulating mechanisms constructed in accordance with this invention are, however, particularly suited for use in signaling systems of the general type contemplated by my Patent No. 2,018,656 dated Oct. 29, 1935..

This invention provides for automatically rendering facilities efiective for emergency operation when malconditions of line circuit or other portions of the circuit appear, for example, such conditions as are usually referred to as short circuits, breaks or the like. The emergency operation may ordinarily supersede regular working with the perfect non-interfering and succession signal transmitting mechanism in the event that the non-interference magnet or its associated parts become disabled. The function and purposes of this magnet and its related parts then being automatically dispensed with during emergency signaling operations. 'I'o'permit these desirable results, test operations may becarried outin such a manner as'to differentiate between a busy condition of the circuit and a malcondition thereof. Furthermore, should the testing operation indicate a malcondition of the circuit, the mechanism is so arranged that it will stop operation after the elapse of a comparatively short interval, thus conserving the en'- ergy stored within the motor spring and preventing needless exhaustion'thereof, so that the motor may be ready'to operate in response to a subsequent pulling of the box.

It is still another object of this invention, when the test operations shall point to a busy condition of the circuit, to provide that effects shall transpireprogressively to limit the number of times a finally successful waiting or seeking box may repeat its signal. These restrictions vary inversely as the length ofthe preceding busy period: for a, first-length of busy period one repetition of a signal shall be deleted; after a. slightly longer busy period'two repetitions ofthe sig-. nal are deleted; proceeding in likemanner; such effects may continue until a transmitter may send its signal but once, without any repetition; and, finally, should the length of the busy period extend beyond a second predetermined time limit, the mechanism of the waiting signal box abandons its attempts to seize the circuit and restores its mechanism to normal, while still retaining enough energy stored in its motor spring for carrying out any subsequent signaling as may be required in the regular eventuations of the service.

A further aspect of this invention relates to the arrangement of the mechanism so that the complete signal may ordinarily be transmitted, even when the current supply is abnormally low, if there is sufficient current to permit initial seizure of the line by the transmitter. Accordingly certain objections which have characterized previous mechanisms of this general type are avoided, since there is little possibility of the transmitter taking possession of the line and sending an incomplete or mutilated code signal, thus giving a false or wrong alarm indication.

More particularly objects of the invention are: To render the non-interference and succession mechanism ineffective in the event of failure of this mechanism to be influenced, by adequate energization of the electromagnet, for a time longer than the longest interval between magnet energizations which should occur incident to the formulation of any signal, to the end that the mechanism may act without the non-interference and succession functions to effect the formulation. of the intended cede si nal notwithstanding any defect or disablement to which the noninterference magnet or its associated mechanism may be subjected; to short-circuit the winding of an electromagnet included in an intended signaling path in the event of the failure of such magnet to become effectively energized throughout a time longer than the longest intended nonenergization interval incident to the formulation of any signal, to the end that in. the event of rupture of the current path through any such magnet winding, the intended code signal may nevertheless be transmitted over the normal metallic circuit, irrespective of the effectiveness of any ground or emergency circuit connection; to provide an emergency common return. or ground connection only following the expiration of a time measured by the running of the train during which the magnet remains deenergized, which time is longer than the longest intended non-energization period incident to the formulation of any signal, and, at the same time estab lish one or more of the other emergency conditions just referred to; to assure effective signal formulation in the normal current path, irrespective of effectiveness of any ground connections, notwithstanding any degree of impairment of the normal line current strength; to provide a non-interference and succession type of mechanism which will act, if short-circuited or shunted out, to effectively transmit the intended code signal between the normal line current path and an emergency common return current path or ground connection; to provide all of the foregoing results without in any wise impairing the socalled perfect non-interference and succession functions, as provided by the most highly developed transmitting mechanisms now known, so long as the normal signaling current path remains unimpaired; to effect conservation of the main spring or other driving power for the transmitter mechanism by provision of means whereby, if the mechanism is: started at a time when the circuit is broken or otherwise disabled, the operation of the mechanism will be terminated after acting to attempt to transmit the intended signal for but a minimum number of times, while permitting action pursuant to the succession mechanism on a busy circuit until a number of attempts to transmit the signal have been made which is the maximum number consistent with the ultimate main-spring capacity, and thus to reduce to a practical minimum the likelihood of the mechanism being brought to rest after having been started on a busy circuit, without having caused effective response to its signal formulation.

In the drawings:

Fig. 1 is a front elevational View of improved transmitting apparatus constructed in accordance with the present invention, certain parts being broken away for clarity of illustration;

Fig. 2 is an isometric View of a portion of the assembly shown in Fig. 1, parts being broken away and removed to show clearly the arrangement of the electrical conducting elements and related parts;

Fig. 3 is a side elevational view of a portion of the assembly shown in Fig. 1, certain parts being removed;

Fig. l is a front elevational View of certain portions or" the signaling apparatus, including portions of the stop train and sender arm control mechanism in non-signaling position;

Fig. 5 is a front elevational View of a portion of the apparatus, parts being broken away and removed and the position of the remaining parts being that which they occupy during a signal transmitting period;

Fig. 6 is a rear elevational view of a portion of assembly, particularly showing a part of the signal train and the escapement mechanism associated therewith;

Fig. '7 is a front elevational view of the signal Wheel;

Figs. 8 and 9 are edge views of the same, showing the relationship of the wheel to a portion of the sender arm;

Figs. 10 and 11 are elevational views of certain parts of the apparatus, showing the position of the same when the signal train is stopped and when it is operating, respectively;

Figs. 12 and 13 are views similar to Figs. 10 and 11 respectively, but more particularly illustrating the arrangement of the sender arm control mechanism;

Fig. 14 is an elevational view of certain parts of the apparatus with parts broken away and removed to show particularly the arrangement of a portion of the sender arm control mechanism and a portion of the stop train;

Figs. 15 and 16 are front elevational views of the signal wheel, sender arm and the related electrical contact and conductor assembly;

Figs. 17, 18 and 19 are front elevational views of a portion of the stop train mechanism and related parts, showing these parts under various operation conditions;

Fig. 20 is an isometric View of the master plate assembly; and

Figs. 21, 22 and 23 are typical wiring diagrams.

For the purpose of facilitating comprehension of this invention and illustrating a manner of applying the several improvements thereof to a type of mechanism with which those skilled in this art are familiar, the embodiment of this invention shown by the accompanying drawings and hereinafter described in detail is one utilizing portions of mechanism such as that of the successive non-interference signal box disclosed in United States Letters Patent to Frederick W. Cole, No. 1,244,587, issued October 30, 1917. Portions of such mechanism which are clearly illu trated and described in said Cole patent are not always herein described in detail, except in instances in which such elements particularly relate to parts of the mechanism more particularly representative of this invention.

Notwithstanding the disclosure of the application of this invention to mechanism such as that of said Cole patent for the reasons just explained, it should be understood that this invention may be practiced with forms of mechanism other than that herein shown and described in detail; and that various aspects and features of this invention may be utilized separately or in groups consisting of less than all thereof.

Motor and signal train The motor means and a portion of the signal train may be similar to that disclosed in the above-identified prior Cole patent, as shown in Fig. l, the outer end of main spring I is fixed to a stud 2 anchored to the outer irame'plate 3 of the assembly, the inner end of this spring being attached to the main shaft l (Fig. 3). The ends of shaft 4 are journaled in front and rear plates 3 and 3 these plates being held in spaced relation by struts ill. The winding handle 8 may be turned counterclockwise, as viewed in Fig. l, to wind the spring I to condition it for imparting a clockwise movement to shaft 4 when the spring is released. A gear ll cooperates wi h a rotating pinion l3 and carries a stop pin ii for engagement with an arm i l moving with said pinion to prevent overwinding in the manner described in the above-identified patent.

A. ratchet wheel 5 secured to shaft 4 engages a, spring-pressed pawl that is pivotally mounted on a spur gear 1 free torotate on shaft 8 (Fig. 6). The gear wheel l meshes with a relatively small pinion ill on the shaft ll, which carries the signal wheel l8 (Figs. 1 and 3). A gear wheel is secured to shaft I'i meshes with a pinion 2i fixed to shaft 22 and to the escapement wheel 23. The latter engages a speed limiting pallet 26 (Fig. 6) mounted on a pivot 26, arms 21 and 23 extending from this pallet and bearing respective adjustable weights SI and 32 to affect the speed of the signal train and thus control the speed of the signal wheel l8.

Manual control A lever 33 is disposed front of the frame plate 3 and connected to a pivot shaft Bil, th latter carrying a projection 36 which has a cam-like engagement with a rocking or master plate 37 to swing the latter clockwise (Figs. 1 and 5). Plate 31 is mounted on a pivot 38 (Fig. 20) that is rotatably mounted between the front and rear plates 3 and 3 while an arm H32 moves with said shaft 38 and has a hooked projection engaging the end of retractile spring 52, the opposite end of which is connected to a pin projecting from plate 3 Plate 3'! is disposed directly behind plate 3 and has an extension afifording a tracer arm 39 (Figs. and 11) which may ride the dished periphery of or enter a notch 42 in a rounds measuring disk 4! that is rotatable on but independently of main shaft 4. A stop dog 4%] has a pivotal connection #33 with the plate 37 and is simultaneously shiftable from engagement with the stop pin 44 projecting from gear whee1.l9 whenithe.

tracer arm 39 is withdrawn from the notch 52, to permit the signal train to start operation under the action of main spring I. When the arm 39 of the master plate moves into the notch 42 of the rounds measuring disk M, the stop dog ll) is brought into the path of the pin 44 upon the wheel l9 to arrest and retain the mechanism in its inoperative position. When the notch 52 has moved out of registration with the arm 39, the tension spring 52 presses the end of said arm against the flanged periphery of the measuring disk 4|, thus retaining the master plate in its operative or clockwise position and affording brake means for the disk to prevent overrunning thereof.

The stop dog ill is substantially in the form of a bell crank and has an arm on with a bifurcated end loosely engaging the escapement--wheel shaft 22. The dog also has a slotted bearing portion 1G engaging the pivot stud 43 that projects from plate Bl, and cooperating with a coil spring 53 which is looped about a boss concentric with the pin 53. This arrangement affords a clearance between walls of the slot at the end of arm it and the shaft 22 and permits the end of dog dil I to snap away from the pin 4 's with a positive and rapid movement; thus preventing reengagement of the end of stop dog 46 with pin 44 and assuring positive release of the train irrespective of how quickly the pull handle is released after pulling.

The use of the stop pin 55 upon the gear i9 is particlularly advantageous, since the strain from the spring 5 received by the pin, the dog M and the related parts is comparatively low due to the gear ratio between gears and i5 and the shafts 4 and H, respectively. Furthermore, stressing of the arm 39 in response to the normal compression or stress of spring lis. avoided; accordingly the plate 3'5 may readily be moved to its clockwise or operative position, while the pivotal arrangement of the stop dog permits it readily to be snapped out of position, this movement being aided by the tendency of gear l9 and pin lit to rotate under the influence of the main spring.

Signal wheel assembly The signal wheel l8 may be cletachably secured by a set screw 29 to the outer end of shaft I], thus to permit ready interchangeability (Fig. 5), and is provided with a plurality of teeth 3c in accordance with the distinctive code signal that is to be sent from the individual box. The sender arm or automatic key 9| is pivotally mounted upon the front plate 3, as indicated by numeral 52, and is provided with a lug or fluke 93 (Figs. and 16) which is engageable with the protuberances 38 on the signal wheel. An insulating block or abutment 94 secured to arm 9| engages the twin contact springs 6'! and 553 (Fig. 2) thereby to set up pulsations in electrical current, as will presently be described, while these springs yieldably urge arm 9! toward wheel l8.

A member 9G depends from the lower end of the sender arm 9! and normally abuts a stud 91 (Fig. l) projecting from master plate 31, so that the latter in its normal position holds the lever Q! and fluke 93 out of engagement with the signal wheel 5 while holding the abutment 94 against the stressed springs 6'? and 63 of the pulsating contact assembly PC. A shield 53 is secured to the rear face of the signal wheel [8 (Figs. 1, 8 and 9). This shield is formed of resilient sheet metal, which is folded back upon itself so that one leg or planarv portion thereof engages the rear face of wheel l8, while the opposite leg yield-ably presses against the first leg, as well as providing a skirt Hill extending beyond a pcripheral portion of the wheel H8. The end of this skirt has an advanced, inclined corner portion llli. When the master plate 31 initially moves out of its normal position to release the arm 9|, the edge of skirt Hit engages the fluke 93 and holds the latter spaced from the periphery of the signal wheel l8, while the contacts of assembly PC remain in engagement under the action of their supporting springs. As shown, the wheel I8 is provided with a continuously curved, void or interdental space adjoining the skirt. After the wheel it is rotated so that the skirt illi) no longer is disposed adjoining the fluke Q3, arm ill may, under certain conditions, swing toward the wheel, so that, during subsequent revolutions, the lip or inclined corner It! of the skirt may engage the fluke with a cam-like action, the shield thus being stressed and engaging the inner face rather than the edge of the fluke (Fig. 8), thus permitting said skirt N36 to be rotated past said fluke without thereby either lifting or supporting said arm ill.

Electrical connections Referring first to the typical wiring diagram of Fig. 21, it is to be understood that a plurality of boxes or instruments 0, D, E, F and G, such as disclosed and described herein, are arranged in series, the parts of the box E being shown diagrammatically. The boxes as thus connected, are jointed by main leads B and H to the respective sides of a central battery CB, the lead B operating a signal-responsive or recording device A at one side of the battery and the lead H similarly operating a device J. The emergency working switch EW, as shown in Figs. 21 and 23, has a contact K connecting the line section H with the left end or minus terminal of the battery; but is adjustable (Fig. 23) so that the ground connection or common return CR may be connected to this terminal of the battery by the engagement of elements L and K, while the conductors H and B are then connected through element M with the opposite battery terminal. The devices A and J may be capable of transferring signals received from the outlying boxes in any well-known or desired manner, as by visual, audible, recorded or any suitable combination of such forms of signal manifestation.

Fig. 2 illustrates more particularly the connection of the external leads to the individual signal transmitting apparatus and also the arrangement of electrically conductive components of the apparatus. The terminal may be connected to an exterior line section, such as the section B, while a similar terminal 5'! is connected to the opposite line section, as the section H. A third line section or common return, such as a ground conductor, may be connected to the third terminal Terminals a5 and. 51 include rectangular plate portions arranged to clamp respective double sets of contact springs 6! and 62; b3 and 64 against a block Eli of insulating material, which is secured to the front plate 3 of the assembly. Block 56 has a substantially right-angular form (Figs. 15 and 16), the contacts or terminals 56 and 57 being secured to the outer face of the depending leg of the angle, while the terminal 58 is secured to the upper part of the horizontal leg of this angle. Angular contact springs ill and 68 are secured by terminal post bars H and 12 against the lower surface of this horizontal leg of the m sulating angle 66. The springs 61 and 68 are arranged so that their depending legs, which follow arm 9| as previously described, also provide contacts normally engaging similar contacts at the lower ends of springs 62 and 6 1, respectively, (see Figs. 2 and 15), while the horizontal legs of springs El and 68 are turned up to provide contacts l3 and M of the emergency switch assembly, indicated generically by reference characters ES. A spring member H is clamped to the block 66' by the terminal member 58 to serve as a third contact element of the switch ES, Figs. 1 and 2.

Secured to the master plate 37, a block of insulating material '19 carries a return bent resilient member 8!, the free end of which is bifurcated to form two contact springs 82 and 83, normally to engage the respective contact members GI and S3. The member 8% forms a shunting conductor, and since it is movable with the master plate 37, it normally engages the contac'tors 6i and 63, thus joining the line terminals 55 and 57 and shunting out the circuits of the transmitter unit. In a converse manner, when the master plate 31 is rocked clockwise, the member 8! will be retracted from the line springs 61 and 63, thereby removing the shunt from the transmitter.

This switch is commonly referred to as the boxshunt, and as its actuation occurs only in the operation to effect an off-normal. condition of the transmitter mechanism, it will be indicated by the appropriate functional reference characters ON.

On removal of the box shunt as just described, a path may be traced from line terminal 56 over the normally engaged contact springs 62 and Ell, terminal post bar ii, conductor 84 to the two serially connected magnet coils 86, of a master magnet MM, thence over a conductor 87, terminal bar it, and the other set of normally engaged contacts provided by springs 88 and E4, to the other line terminal 51. Thus, the first two line circuit sections may be joined, at certain times, through the magnet MM in completing a loop circuit, the current in which causes the magnet to attract its armature 88, and thereby initially condition the transmitter to operate in a standard or normal manner. The non-interference magnet MM serves divers major functions and is of universal utility in the present mechanism; accordingly, it may also be referred to by this functional term, master magnet.

Sender arm control assembly The armature 38 normally is drawn away from the magnet MM by a spring I I2 and has integral levers I62 and I533 rocking about a pivot element IM- (Figs. 5 and 11), one of the struts H3 acting as a stop to limit the movement of the armature under the tension of spring H2 (Fig. 1). The lever IE2 is movable into and out of the path of a guard pin I36 which extends rearwardly from the upper end of sender arm 99 and which has a flat surface adjoining the end of arm I02. The lower end of lever Hi3 provides an outturned ledge IE7 movable into the path of a swinging pawl H38 pivoted at H9 (Fig. 13) on the lefthand end, as seen in Figs. 5, 11 and 12, of a latch member IEIS. When the current flowing to magnet MM is uninterrupted as the signal train starts operation, the ledge I0! is disposed below pawl Hi8 and the pawl may rest thereon, so that the right-hand end of the latch member is held beneath the path of guard pin I86, despite the tension of spring I28 connecting this end of the latch with the plate 3 (Figs. 5 and 12). Thus,

when the armature is juxtaposed to magnet MM, the lever IE2 is disposed above the path of the guard pin I 09, while the end of latch I09 may be disposed beneath this point (Fig. 5). Accordingly the path of the pin may be cleared so that sender arm 9I can reciprocate.

The contacts provided by springs 62 and 64 remain in engagement with the sender contacts provided by springs 61 and 98 for an interval surficiently long after the sender arm 9! has started its movement toward the left in beginning an impulse formulation, to permit the guard pin I06 upon arm 9| to pass beneath the right-hand end of lever I02 before separation of the contacts occurs. Accordingly, when these contacts separate and effect deenergization of magnet MM, the lower surface of lever I02 rides upon. the upper surface of pin I06 through the remainder of the sender arm stroke towards the left and the return portion of this stroke (Fig. 16) until the contacts of switch PC have again moved into mutual engagement. Thereupon reenergization of magnet MM takes place so that the armature 83 is electrically retained in its portative position.

- While the armature 88 is thus continually held in its attracted position, the free end of the lever I02 is withdrawn from the path of guard pin I 98, and ii the latch I09 has: previously been withdrawn from the path of said pin I99, it will be held out of such path by the engagement of the lower end of the pawl I98 with the ledge I91 carried by the arm I03. The sender arm will therefore be free to operate in response to rotation of the signal wheel I9 so long as the positions of the parts just referred to remain unchanged.

Normally the actuating cam H3 is at rest beneath the projection I21 of lever I09 to prop the latter against the tension of rotator spring I28 (Fig. 12). Slight advance only of the signaling train from normal is sufiicient to move cam H3 beyond fluke I21, so that unless otherwise stayed (as by-engagement of pawl I08 with ledge I07! when armature 88 is in its portative position), the member I99 may swing to its blocking position, where its right end is in the path of guard pin I96 and where it encounters the stop pin I34 fixed to the frame plate 3 (Fig. 13) In this position the left-hand end of member I09 supports the depending end of pawl I09 in the path of the intersecting extension l0. of lever I93, and also in the path of the angle I24 at the end of restoring lever I22. A pawl II4 pivoted at IIS on plate 3 is engageable by the cam II3 an instant after it starts rotation, so that when the latch lever I99 is in its blocking position the pawl is lifted and its projection I I1 is seated or latched on a ledge H8 (Fig. 14) of the latch pawl i68, as shown in Fig. 13. The retractile spring H5 continually tends to swing pawl I I4 counterclockwise on pivot I I6, so that it tends to project into the path of the actuating cam II3, while the tension spring l29 connects an ear on member I08 with the pivot pin I2I that supports latch I99, thus yieldably swinging the upper portion of member I08 toward the projection Ill and toward or against a sleeve on armature pivot I64, which acts as a stop.

In order to permit the latching just described, the dual purpose stud 91 of the master plate 31 projects between the extremes of the bifurcated end of the latch restoring lever I22 (Figs. 5 and 13) pivoted to the frame plate 3 at I23 and serves, in the off-normal position of the plate 37, to rock the lever I22, swinging its upper or free end to the left, so that an angle 124 thereon may be withdrawn from its normal abutment against the lower end of the pawl member I08 (Figs. 1, 5, 12 and 13). This permits the spring I26 to swing the upper end of the member I98 to the right for latching the lifted switch pawl II I, as just described.

When the armature 88 is rocked on the pivot I 94 due to momentary energization of magnet MINI, the projection I91 oi the lever I 93 moves to the right against the depending end of the latch #98 to eirect counterclockwise movement of the latter member, thereby withdrawing the latch-ledge 1E9 from the keeper I'I' of the switch actuating pawl H4. This action completes the cycle of busy test operations for the first round of the signaling wheel i3, and in these operations the ground switch actuator H9 is lifted and latched in an intermediate position and subsequently released to return to normal position in preparation for meeting other than a busy condition on the line. Description of the latter effects will presently be continued. The unlatching of the switch actuator H4 at this time merely indicates that the only non-normal condition of the line circuit found to be present by the busy test operations was that of busy line. All of the operations just described occur during a relatively short interval during the initial round of the signal train, and if the current flowing through terminals 56 and 5'! is interrupted due to the operation of another transmitter, the locking lever or guard I99 remains in thepath of the guard pin I06 to keep the sender arm 9! ineffective during the remainder of this first round.

The busy test operation just described will be repeated at the beginning of each round of the signal wheel I8, as the signaling train continues to run and constitutes successively repeated attempts of the present transmitter to seize the circuit for immediate use. At the end of each round, the cam H3, in passing under the tracer I21 of the sender lock I09, rocks the latter clockwise momentarily to remove the right-hand end of this member from the path of the guard pin .109, in presenting the sender arm SI for possible control acceptance by the signal wheel I8. The completion of the round or cycle of the signal wheel occurs at a time when the shield 98 supports (as will be hereinafter more fully explained), on its edge, the tracer 93 of the arm 9| to prevent movement of said arm toward wheel I8, and since the first round was ineffective to send on account of the busy condition assumed to having been encountered, the lever I 09 continues to prop the sender arm 9I in its ineffective position until entire completion of the round. At the latter instant, the shield 99 is again in the position in which it is shown in Fig. 1, where its skirt I00 supports arm 9! while lever I09 is being withdrawn from the path of the guard pin I06. Therefore, under the continuing operation of the signaling train and at the beginning of the second round of the signal wheel I8, the various parts concerned in the testing operations will be in the same positions in which they were at the beginning of the first or initial round.

The edge of shield I00 has a slightly eccentric contour at It) I, so that the advance portion thereof may engage the fluke 93 with a cam-like ac tion, moving the pin I06 slightly to the right out of engagement with latch I09, so that the latter may freely move under the action of cam M3 to its non-blocking position. The pin I06 and arm 9| may occupy any one of five positions: first, the normal position wherein pin 97 engages tailpiece S6 and the fluke 93 is slightly spaced from shield 98 (Fig. 1); second, the position wherein the fluke 93 rides on the edge of the shield (Fig. 15); third, the position wherein the pin I06 engages the end of arm use (Fig. 13) fourth, the position wherein the fluke engages the top of a tooth of wheel I8; and, fifth, the position wherein the fluke engages an interdental surface of wheel I8. In the first four positions the contacts of assembly PC may remain closed; in the last position the contacts are separated.

Ground switch control When the armature arm S02 and the latch 59 are disposed in the path of pin I 86 due to the armature being in its raised position, the cam H3 may engage the projection It? and thus rock the member IE9 clockwise. The upper surface of the projection Ill of switch actuator H4, if it has remained in its lifted and latched position on the ledge I I8 of member I08, will then be elevate to its actuating position against the lower edge of a projection I36 on a switch latch lever 83? pivotally mounted on frame plates 3 and 3, as indicated by numeral I38 (Fig. 11). The elevation of the left-hand end of member I 89 then thrusts the extension H7 against projection I 3 5 to rock lever I 3! counterclockwise. Thus, the switch actuator I I4 is lifted in two steps, the first resulting in the latching on ledge H3 (from which it is dislodged if magnet MM is momentarily energized to swing part Isl against pawl I08), the second step occurring after substantially one revolution of cam II3 following the first step and involving the engagement of the cam II3 with the fluke of latch I89 While the member H4 is supported by ledge H8. Accordingly, the movement of actuator I id to rock lever I31 will only occur if the magnet MM has remained deenergized during substantially one revolution of the shaft IT. The upper end of lever I3! is curved to provide a keeper for retaining cylindrical contactor or switch member I8 in its ineffective position, as shown in Fig. 12. The counterclockwise movement of lever l3! accordingly releases contactor I8 and a projection I39 on the lever engages a protuberance I46 from the armature 88, mechanically rocking the armature into its portative position (Figs. 5 and 11).

The contactor I8 is secured to the end of a lever I4I, a tensile spring I42 tending to move this lever clockwise about the pivot 43 carried on master plate 3! (Fig. 5) to thrust contactor I8 into engagement with contact springs 13, I4 and 11, thereby providing an electrical shunt for the magnet and joining the springs 61 and B8 of the switch assembly PC, while connecting the ground terminal 58 with these contacts. When plate 31 is in its normal position, pivot 43 is so positioned that the end of lever MI is carried into engagement with shaft 38, to thereby maintain contactor 18 away from contacts I3, I4 and TI, and in position to freely permit lever I31 to move into latching position in the path thereof, so long as plate 37 is in normal position. The free end of lever I3I has an inclined end engaging the contactor 18, such end being so formed that during move ment of the arm MI responsive to spring I42, as the contactor I8 passes along said inclined surface it will cause the arm I31 to swing somewhat in a counterclockwise direction and thereby act through the extension I39 moving with said lever I31 and the flexible strip M8 associated with the armature 88, to firmly hold said armature and its associated assembly in portative position and, at the same time, to stabilize contactor I8 in engagement with the contact springs "l3, I4 and I1. While the armature assembly is thus maintained in its portative position, the ledge I8! carried by the lever I83 is disposed in the path of the lower end of the pawl I08 and thereby prevents the descent of the latch lever H19 at times when the support of the cam H3 is withdrawn from the projection i2! of said latch lever; with the result that neither the free end of said latch lever I09 nor that of the arm I62 will be disposed in the path of the pin I06, and the arm 9I will be free to move in response to the rotation of the signal wheel.

Stop train and related control mechanism A pawl cam 46 fixed to signal gear shaft ll! has a notch 45 engageable with a pawl 49 that is pivotally mounted on a rotatable member 4? in loose assembly with the shaft Il (Figs. 5 and 14) A spring 50 engages the pawl 48 and thus tends to retain the opposite end of the latter in engagement with the recess 45, to hold the clutch in its closed or operative position, so that the members 45 and All may be caused to rotate as a unit with the signal wheel shaft I1 and the members fixed thereto. Member 41 carries a gear 41 which meshes with a wheel 5| aflixed to the measuring disk H upon the main shaft 4 (Fig. 3). When the clutch 4648 is closed, the signal and stop trains operate together to bring the rounds disk II to its normal position so that spring 52 (Figs. 5 and 10) will rock plate 31, and cause arm 39 to reengage the notch 42, and the stop dog 40 to engage the stop pin 44.

The signal and stop trains preferably have such a gear ratio that the measuring disk t! normally makes one revolution during four revolutions of the signal wheel I8. Under certain conditions, however, the clutch 4648 is open so that the signal train continues in motion while the movement of the stop train is interrupted. Accordingly the signal wheel may continue rotating and tests of the circuit conditions may be made through the armature and latch mechanism, while the rounds or measuring disk 4| remains stationary at one point of its path.

A skipping dog I29 (Figs. 4 and 14) loosely swung on the pivot shaft I94 is continuously stressed clockwise by a rotor spring I3I extending from the dog about a boss concentric with shaft I04 and having its remote end connected to a pin upon the armature lever I82. An arm I32 projects forwardly from dog I29 to engage a sloping extension or fiuke I33 on the upper edge of the left-hand end of latch lever I 09, so that the lower extremity of dog I29 may swing downwardly to engage the pawl 48 when the righthand extremity of the latch lever is raised to its blocking position. Accordingly, the lower end of the skipping dog I29 is then disposed in the path of the pawl 48 so that it may engage the pawl after the shaft I! has made substantially one revolution, thus to disconnect the clutch elements 46 and 48 and cause cessation of movement of the members 41, 41 upon the shaft I1, and of the measuring disk M and its gear 5| upon the main shaft I, the end of stop arm 39 engaging the dish d periphery of the measuring disk under these conditions to act as a brake and prevent accidental forward movement of the same as the clutch is held out.

A counting movement is provided which prevents continued rotation of the signal wheel without effect upon the rounds disk, so that, if line conditions prevent transmittal of the signal after a plurality of rounds of the signal wheel, the mechanism may be automatically stopped to prevent entire exhaustion of the potential energy normally stored in the main spring. For this purpose, the stepping and stop pin 44 upon gear I9 may engage ratchet teeth on a counting wheel i552 that is loosely mounted on main shaft 4, advancing this wheel one step (Fig. 17) under the control of a click element 553 and against the tension of a spring which is adapted to be wound on a grooved hub 55 on the counting wheel. Spring I54 is secured to the element I53 and to a stepping pawl I5l pivoted to ratchet wheel I52 at i533, this spring serving the triple purpose of drawing the ratchet wheel to its normal position, yieldingly retaining the pawl I5? against a stop pin 559 on the side of the ratchet wheel and stressing the holding pawl or click element I53 clockwise against counting ratchet I 52. Element IE3 is stepped to provide two ledges which, together with the end of the pawl, afford three different surfaces which at respective times may engage teeth of the counting wheel I52. The element I53 is pivotally mounted on a pin i555 projecting forwardly fro-m plate 3 this pin also engaging the end of the retraotile spring 52 for plate 37.

An aperture H33 in the body of the pawl 53 receives the angled extremity I53 of the arm !62, which is secured to pivot shaft 38 of master plate 3?. Normally, when the latter plate is rocked counterclockwise, the angle 153 is disposed adjoining the apex of the opening l8 thereby holding the free end of pawl I53 out of the path of a long tooth 564, on the counting wheel I52, while the intermediate ledge or shoulder I55 of the pawl is positioned to engage this tooth I54, in retaining the counting ratchet I5!= in its normal or zeroposition (Fig. 19). Conversely, when the mechanism is off normal, the plate 31 standing clockwise, the angle I53 of the arm 562 is positioned toward the larger end of the opening IGI in the holding pawl I53, thereby substantially freeing this pawl for additional movement to the left so that it may freely engage the teeth of the counting ratchet wheel I52, under tension of the universal retractile spring I54.

Although substantially any desired time or rounds-relation capacity may be afforded by this allotting means, for purposes of illustration, a certain numerical relationship and capacity has been assumed and illustrated in the drawings.

From the normal position in which the allotting means as well as the other mechanism is shown in Fig. 19, the first round of the signaling train may cause the pin 44, in passing counterclockwise, to engage the twelfth tooth, as may be numbered clockwise from and including the long tooth I54 of the counting ratchet I52, thus advancing the latter clockwise one step, so that it will then be retained by engagement of the end of the pawl !53 with the long tooth IE4. During the second round of the mechanism, the pin 44 engages the next lower or eleventh tooth of the counting ratchet l52 in advancing it a second step, whereupon it is retained by engagement of its last tooth I89 with the last ledge I61 of the holding pawl !53, while on the third step of the ratchet wheel I52 during the third round of the signal train, and also during the following successive advancing steps thereof, both of the shoulders I66 and I6? of the holding pawl incidentally may dually engage teeth in retaining the counting wheel as advanced (Fig. 15).

The presence of the interdental or gap-space intermediate the extended tooth IE4 and the last tooth 59 on the counting wheel 52 is the principal reasonv for providing the intermediate shoulder V55 which serves to hold the counting wheel in its normal or zero position and also to cooperate in holding it on succeeding steps, as just described.

During the first eleven rounds, for example, the counting wheel I52 is advanced the distance of one tooth per step, but during the twelfth round the pin A l engages the extended tooth 36%. This ensures ample forward throw and also sufficient rotary sweep of the stepping pawl I512 during the twelfth round to permit it to seize one of the teeth in a tooth-field ill on the periphery of the pinion disk 3?, and thus rock this disk a limited distance counterclockwise as a preliminary step, presently to be augmented during subsequent revolutions of the wheel is by other steps whereby the cam pawl 8, carried by this disk ll, may finally be withdrawn form beneath the angle I46 at the end of the trip dog I25, thus permitting said pawl to move responsive to its spring 5t so that it will he engaged by the disk =16 (see Fig. 14) and thereby effect further rotation of the wheel 5! for the purpose of advancing the disk ll toward the position in which its notch 12 will be presented in the path of the tracer 39.

he interdental space between the long tooth and the last tooth I59 on the counting wheel 52 provides that during each round, subsequent o the twelfth round, the action effected by the pin :5 will be restricted to engagement with this long tooth only, and the positions and propertions are such that, while the wheel 552 may be affected, it will not be moved a full step. Therefore, during the latter rounds, the wheel I52 divides its function as a counting means vrith the disk 61', and also becomes an intermediate link in a train of mechanism for intermittently connecting the pin 44 to the stepping pawl I51. Thus, under such condition each time the pin M sweeps past the tooth le l it causes the wheel 552 to rock, and thereby rake the attendant stepping pawl I5? forward in the tooth-field ill of the disk 4?, thereby to seize and drag the latter disk forward a certain distance, either in preparation for or in conclusion of a series of actuations for clearing the trigger end of the pawl 48 from. the trip dog E29. As the forward rock of the wheel ii]?! is less than a full step, the holding pawl I53 may not fall in but merely ride the point of the next ratchet tooth of this wheel, sought to be presented thereto. Therefore, on the instant the pin. 44 passes from the long tooth 84 and thus releases the then unlatched wheel M2, the spring E54 will cause backlash movement until it is checked by the holding pawl I53 meetingthe tooth of the ratchet on which it was previously seated. During such retraction of the wheel E52, the stepping pawl I5! is moved backward in preparation for a new hold in the toothfield N2 of the disk 47.

Under the conditions just assumed and described the pin 44 engages the long tooth I64 of wheel I52 and advances the counting wheel to its highest or final point against the action of retractile spring 554. Thereupon during the twelfth and succeeding rounds of the mechanism the stepping pawl I5? may be effective in advancing the disk 4'! notch by notch. Thus the disk 3! is advanced two successive notches during the twelfth and thirteenth rounds, this movement being suiiicient to withdraw the pawl 63 from the skipping dog E29 so that the clutch lfi- 'lfi is reengaged, causing the member 4? and gear ti to rotate with the shaft I1 and caus ing a quarter revolution of the rounds disk 4|. Thereupon if the current conditions are such that the skipping dog I29 remains in the same position, the dog again engages the pawl 88, the clutch iiiii! is opened, and for two successive additional rounds the member 47 is stepped along by engagement of the stepping pawl IS! with the toothed portion thereof. At the end of the second succeeding round the skipping dog and pawl are again disengaged, the clutch 4548 is again closed, and the measuring disk makes another quarter turn. lhe same sequence of operations may be repeated at the end of two more rounds so that the measuring disk ll completes its final quarter revolution, whereupon the arm 39 reenters the notch 52, thus causing the dog 40 to be carried into the path of the pin M to thereby terminate. the operation of the mechanism.

Whenever the mechanism is brought to rest under any of the various circumstances herein described through the stop dog 40 being moved into the path of the pin i l, the accompanying clockwise movement of the plate 3! in carrying the arm 39 into the notch 12, correspondingly swings the arm M32 so as to change the relationship between the angled extremity 163 of said arm and the aperture 555 in the body of the pawl @53, from that shown in Fig. 18 tothat shown in Fig. 19, and. thereby causes said pawl M3 to swing away from the ratchet Said ratchet will thereupon. be rotated counterclockwise, by its spring we, until it is restored to its normal position where its long tooth 164 engages the intermediate tooth Hit of said pawl I53.

It is evident that the signaling apparatus may transmit three rounds of the signal through the pulsating contact assembly PC, if the rounds measuring disk has been moved one-quarter of a revolution before transmittal of signals through this assembly is permitted. If the rounds wheel or disk has moved one-half a revolution before the transmitter receives possession of the line, two rounds of the signal will be transmitted, and if the disk has moved three-quarters of a revolution, only one round will be transmitted. Accordingly, this arrangement results in the repetition of the signal for a smaller number of times after a determined period of delay, the number of repetitions being reduced as the: period of delay is prolonged until but a single round of the signal may be transmitted, and ultimately the mechanism may be conditioned so that the signal will not be sent at all, but the signal train will stop to conserve some of the potential energy stored in the main spring I for a subsequent operation.

Ordinary operation If the starting lever 33 is pulled, when the line circuit is in normal condition and no other transm tter associated with that circuit is in operation, the apparatus will operate in the normal manner to cause immediate transmittal of the signal. Pulling of the handle 33 swings the master plate 3'! in a clockwise direction, removthe stop arm 39 from the notch 42 in the rounds disk 4| and snapping the stop dog 30 out of the path of the stop and stepping pin on gear l9 (Fig. 11). Movement of the plate 31 also disengages the contacts of switch ON and removes the pin 91 from the tailpiece 96 of the sending arm 533, as well as swinging the angle E24 at the end of latch restoring lever M2 to the left, from the depending end of pawl it. As soon. as the stop dog "all is removed from the pin l4, and the arm 33 is retracted from notch E2, the signal train starts turning, due to the release of energy from main spring l. The shunt connection provided by member ti with its contacts S2- and #33 is disconnected by opening the switch (3N so that current flows through the contacts of the pulsating contact assembly PC, the arms 9' i, it, and the connections 84 and 8?, whereby magnet MM is energized. Armature S8 is thus immediately drawn to its portative position, the fluke 93 of sender at having been moved into engagement with the skirt led by the springs 33 and 63 as soon. its tailpiece was released from engagement with the pin W. The energization of magnet MM raises the arm hi2 so that the guard pin led may pass under the end of this arm. When the shaft ll starts rotating from its normal position, the cam IE3 moves out of supporting engagement with the fluke l2! carried by latch lever or guard. Hi9, so that the low-er end of pawl HIS may engage the ledge iii? of armature lever H33, which has been. moved by e-nergization of magnet MM into the proper position to receive the lower end of the pawl. Thus the right-hand end of arm IE9 is locked in its depressed position.

Accordingly the path of guard pin M6 is cleared, the latching lever being held below its path, and the energization of the armature holding the arm H32 above its path. As soon as the fluke 93 leaves the skirt Hi8, it may engage the periphery of the signal wheel, opening the contacts of switch assembly PQ so that the magnet is no longer energized. However, under these conditions, the armature 88 is mechanically held in its portative position, due to the end of lever H32 resting on pin I06. As one of the teeth 3i] moves the arm 9i to its switch closing position, the contacts of assembly PC are again momentarily closed to energize the magnet MM to permit the armature to be electrically retained in portative position. before its mechanical support provided by the parts I02 and WE becomes inoperative. Thus the electric pulsations are sent over the line or electrical loop provided by conductors B and H, so that the signal devices A and J in the main station may be energized to indicate and/or record the signal being transmitted.

The skipping dog 529 is held out of the path of pawl 48, due to the position of latch lever Hi8, so that the clutch tit-4B remains in its closed condition. Accordingly the gear 41 rotates with shaft ll, so that the rounds disk makes one revolution in four revolutions of the shaft l7 and the signal wheel. Accordingly four rounds of the signal are transmitted before the notch 12 again receives the stop arm 39, thus permitting the plate 3'! to returnv to its normal position and to move the stop dog Q into engagement with the pin 44 (Fig. 19). Simultaneously the shunt switch ON is closed, the stud 9'5 reengages tailpiece !zt, and the projection I24 at the end of arm 22 swings against the lower portion of pawl IE8 positively to return the latter to its inoperative position.

Due to the ratio of gears i and iii, the shaft ll of the signal wheel [8 may move through the four revolutions or rounds while the main shaft 4 is moving but a fraction of a revolution, for example, substantially one-half a revolution, so

that the spring I has a sufiicient capacity to send many signal rounds under ordinary conditions. In this connection it is to be noted that the measuring disk ll and its gear 5I normally rotate faster than the shaft 5 upon which they are loosely mounted.

While the armature lib may be drawn to its portative position, even if the line current is comparat ely weak, it is evident that an even weaker c ent may be effective in holding the armature in portative position. Accordingly this apparatus is not likely, under weak current conditions, to obtain possession of the line and then transmit an incomplete or mutilated nal, but if the current is sufiicient to sheet line seizure, the armature will not be to move to retracted position, as a resuit of impair d line current strength during signaling impulses, unless the extent of such impairment is far greater than that in effect at the time of the commencement of the transmission of the signal.

Operation when transmitters are in interfering relationship If the control lever 33 is pulled when the circult is in possession of another transmitter, the switch ON is opened and the signal train, including the wheel i3, is set in operation in the same manner as described above. Similarly the ledge I'M of restoring lever 322 is moved away from pawl Hi8. Due to the possession of the line by another transmitter, there will be pulsations in the current passing over the line, so that circuit may be intermittently closed and the magnet MM intermittently and momentarily energized. The extent of the portion of wheel is adjoining skirt I is so related to the speed and spacing of teeth in the signal wheels of other transmitters that there is at least one momentary deenergization of the magnet MM while the fluke 93 is being supported by the edge of the skirt EGG if one of the other transmitters has prior possession of the line. Since the line is thus opened, however, the magnet MM does not remain energized and the armature t8 moves to retracted position, causing the arm IE3 to carry the ledge Idl to a position where it no longer supports the lower end of pawl Hill. The rotation of H5 permits the left-hand portion of arm lll to drop and the right-hand end thereof to rise into its blocking position almost as soon as movement of the shaft H is initiated; thereupon the cam iii-l engages the lower extremity of ground switch actuating dog us, raising the latter to its intermediate position where the projection l l? thereon is lifted above the keeper ledge l it carried by the pawl Hi8, which then moves responsive to spring I26 to carry said ledge into the path of said projection Ill (assuming that the magnet MM is at this time denergized in response to an interruption of the circuit incident to the operation of another transmitter), thus performing the first step the process or li ing the member l I4 to its switch closing position. If the magnet MIL/1.5.5 energized at the time when the switch actuating dog lid is by the lit, as just described, the armature will he in its portative position, so that the ledge it"? on the arm H33 will engage the lower end of pawl Hi3 and thereby prevent the ledge H8 from being carried by said pawl into the path of the angle Ill while the dog lid is in its elevated position. If, however, the magnet MM is denergized at a time when the dog lie is raised by the cam H3 as just described, upon the occurrence of further pulsations in the exterior circuit during continued rotation of the shaft H, the armature 88 will be momentarily drawn to its portative position, and the ledge Ill! on arm I03 moving with said armature will strike the lower end of pawl I93 and thereby swing said pawl so as to disengage its ledge l l8 from the angle I ll of member I M, which member will thereupon return to its previous normal position. Thereafter, when the cam II3 next engages the member lit, the latter will merely repeat the first step of its movement.

During the beginning of each successive round of the signal wheel when the transmitter is prevented from seizing possession of the line, due to the prior possession thereof by another or other transmitters, the latch lever IE8 is momentarily engaged by the cam II3, so that its right-hand end (Fig. 12) is moved downwardly against the tension of spring I28 to permit the pin iSE and sender arm 9! to move to the left unless otherwise prevented. At such times, however, the fluke 3 engages the edge of skirt I60, thus preventing such a movement of the arm and pin. If, however, the transmitter which has had possession of the line relinquishes the same, the magnet MM becomes permanently energized, the arm- Hi2 being held above the pin it; thereafter when the cam II3 next engages the fluke 93 and guard E69, it will depress the blocking extremity of the latter, and the lower end of the pawl I E38 is engaged with the ledge ldl to retain the latch lever in its non-blocking position. This operation takes place while the edge of the skirt I80 engages the fluke 93. Thereupon the fluke may leave the skirt sothat it engages the teeth clements 3B of the wheel It in the normal manner.

As described above, the operation of the signal train may continue if the line is busy due to possession by other transmitters, or if pulsations in current similar to busy signals cause momentary energization of magnet MM. For example, the shaft ll and wheel I8 may rotate for as many as twenty-three turns before the stop train and counting mechanism have been effective in causing the disk i! to turn through one revolution, so that the apparatus is stopped by a reengagement of the arm 39 with notch 42 and the dog 43? with pin M. After the signal wheel has thus been rotating in an idle manner, without transmitting signals by means of the reciprocation of sender BI and opening and closing of the contacts of assembly PC, the number of signal rounds which may be sent by the transmitter is automatically reduced.

Thus, as described above, after one or substantially one revolution of the shaft Il, the pawl 48 may engage the dog I29, which is held in the path of the pawl due to the latch-lever its being in its blocking position. When the pawl 43 is thus engaged, the clutch 45-48 is opened and member 'l with its pinion M the gear 5! meshed therewith, and the rounds disk ll may remain stationary, although the signal train continues its movement. However, each rotation of the gear I9 causes the pin 44 to engage a tooth upon the periphery of counting ratchet wheel I52 (Fig. 1'7), thus to cause the gradual movement of the latter against the action of retractile spring ISA, holding pawl I53 acting as a ratchet to retain the wheel I52 in its advanced position. Thus the counting mechanism may be effective to cause the counting wheel I52 to advance step by step or tooth by tooth, without any other definite result for a number of rounds of the signal train, as long as the line is busy. If at any time during this period the line should become clear, the armature is moved by energization of the magnet MM to such position that the ledge Iii'l will be disposed in the path of the lower end of pawl I98, to be engaged by said pawl to thereby support latch arm I69 in its elevated position after said arm has thereafter been next raised by the action of cam I I3, so that the right-hand end of said arm will be moved downwardly to a position where it will no longer be disposed in the path of pin I06 and restraint of movement of the arm 9i will be terminated. Such movement of said arm IE9 will also carry the sloping extension or fluke I33 moving therewith into engagement with the arm I32 carried by the skipping dog and thereby move the free end of said dog out of the path of the pawl 48, so that the clutch iii-48 may then be closed, whereupon the mechanism will operate in the normal manner. Inasmuch as the occurrence just described takes place when the notch G5 in the disk it has just passed beyond the free end of the pawl :18, the closing of the clutch 45- 38 will not become effective until the signal wheel I8 has thereafter completed nearly a full revolution, and has thus sent a round of the signal. After this, but three additional rounds will be sent from the transmitter, since the disk 4! had already made a quarter of a revolution at the time the skipping dog I29 was positioned to permit closing of the clutch -43, and since no more than one round is sent out to each quarter revolution of the disk.

If the line should still remain busy, the counting ratchet wheel E52 will continue its tooth-bytooth movement until the long tooth IE4 is engageable with the pin M, which throws the hooked or raking ratchet I52 into engagement with the toothed field I12 on the disk 41 (Figs. 4% and 13), thus to cause a movement of the member ii, the parts being so proportioned that the wheel 552 is advanced less than a movement corresponding to a single one of its ordinary teeth, so that the ratchet element I 53 permits a slight backward movement of the wheel I52 under the action of spring I54. In the course of the next revolution of the wheel IS the pin 44 engages the long tooth I54, causing the hooked ratchet I51 again to engage the toothed field I12, thus moving the disk A? far enough to disengage the pawl from the skipping dog I29, permitting clutch tte8 to close, so that when the notch 45 is next presented to the free end of said pawl near the conclusion of the next revolution of the gear it, the member 41 with its gear W will be caused to rotate for one revolution, thus turning the measuring disk 4| for a quarter of a revolution. Thereafter, if the line is released so that it may be taken possession of by the transmitter, but two rounds may be sent by the signal wheel after the notch 45 is presented to the free end of said pawl 38, since the measuring disk has made one-half a revolution. If, however, the line remains busy, the step-by-step movement of the disk 41 is repeated twice, due to engagement of the pawl I5! therewith, whereupon the clutch itii? is again closed and the disk ii turns another quarter of a revolution, so that thereafter but a single signal round will be given if the line is released to the transmitter. After two more rounds, which result in another closing of the clutch Ma -GB, the shaft I'I enters its final round, the disk M passes through its final quarter revolution, and then the notch 42 is again presented to arm 3d. The transmitter may gain possession of the line to send a signal until the cam I I3 leaves the fluke I27 of arm I35 at the beginning of this final round, corresponding to the final quarter revolution of the disk 4|.

The arrangement just described will also be effective to prevent interference between two transmitters should both transmitters be operated at the same time or, in effect, simultaneously. Under these conditions the sender contacts PC of both transmitters may at first operate in synchronism, as in any case of nor mal operation. If, for example, the two transmitters have signals presenting similar digits, when the initial teeth of the wheels l8 of the respective transmitters are withdrawn from their respective fiukes E3, both transmitters may at first operate in synchronism. For example, assume that one transmitter sends signal pulsations according to the formula 2-35, and assume that the other transmitter sends a signal 2-2-5; both transmitters may operate together until the 2 of the second digit has been sent. Thereupon the line will be held open by the transmitter sending the signal 2-25, for a time longer than the interval between consecutive strokes of any numeral, so that the movement of the sender arm 9i of the other transmitter for effecting the third closure of its contacts for the second digit 3 will occur at a time when the circuit is open at the transmitter sending the signal 225. The armature of the 235 transmitter will be released from its magnet MM and the parts thereof will then occupy the position which normally is occupied under line busy signal conditions until the first transmitter has completed its signal. Thereupon the other transmitter may automatically seize possession of the line and send the signal for four complete rounds, or until its measuring disk M has made one revolution.

Emergency operation When there is a break in the line circuit so that current may not be received by the magnet MM even momentarily, as would be the case where the line under a busy condition, the mechanism automatically operates to close an emergency line which normally may be in the form of a connection to a common return conductor, such as the ground. When the box is pulled under these conditions, the initial position of the parts may be the same as described above in connection with a busy test or when. boxes are in interfering relation. The skirt IE0 is disposed in blocking relationship to the fluke 93, thus preventing the movement of the arm 9| to a position where the contacts of assembly PC will open.

As the shaft I'i starts rotation, the cam II3 leaves the fluke I21 of the latch arm I09, permitting the latter to rock counterclockwise under the action of spring I28, so that the end of arm M39 is disposed in blocking relation to guard pin ice to prevent movement of sender arm GI when the skirt Hi6 passes out of engagement with the fluke 93 (Fig. 13). The cam H3 under these conditions is effective in lifting the ground switch actuator I I 3 to a position where the projection I I1 thereof is latched over the ledge I I 3 upon the pawl Hi8, the projection I24 of restoring arm l22 and the projection It! of armature lever I03 being positioned to permit the latching of members IM and IP18 in this manner as the shaft I'i starts rotation.

When the cam I53 has substantially completed one revolution, during which the clutch 46-48 has been disengaged, the skirt Hill is supporting fluke 93, the cam H3 engages the fluke I27 of the latch-lever Hi9, rocking the latter clockwise, so that the switch actuator H4, which is now supported in its intermediate or latch position (and which has not been dislodged from this position since the annatur'e has remained retracted due to the absence of even a momentarily line current), will be lifted to a position where it engages the lever I37, lifting the latter against the tension spring H5 so that the switch arm Hll may swing about its pivot 43 to move contactor it into engagernent with contacts 73, M and TI, thus closing the ground or emergency switch. The lifting of latch H39 also moves dog I29 away from pawl 48 (Fig. 4), so that clutch Ali-i8 is reengaged and rounds disk 4| starts rotating when the notch 45 has again been presented to the free end of said pawl 48.

Under these conditions the inclined end of member I31 has a cam-like engagement with the cylindrical support for the contactor It, thus acting as a prop to hold armature 88 in its porta tive position (Fig. ii), the armature being moved and held by projection i353 on arm I31 engaging the armature spring Mil. Further rotation of the cam I I3 will thereupon withdraw it from engagement with the fluke I21, thus permitting the arm I09 to move responsive to the spring I28 until the lower end of the pawl Hi8 engages with the latch end ill! of lever Hi3; thus preventing movement of said lever to position where its free end would be disposed in the path of pin Hi6 and finally clearing the path of movement of said pin; the free end of armature lever I82 having been previously withdrawn from the path of said pin when the armature was moved to attracted position through the action of projection its moving with arm I31. Thus when the skirt I58 passes out of engagement with the fluke 93, the sender BI is free to move to its circuit opening position and may oscillate in response to the contour of the wheel i8, intermittently closing the contacts of assembly PC in response to engagement with the teeth 3i distributed upon this wheel. Such movement of arm IE9 caused its sloping extension I33 to act against the arm I32 carried by the Skipping dog I29 to swing said dog to its inoperative position and thereby permit closure of the clutch ifi8, which closure becomes effective when the notch 45 is then next presented to the free end of the pawl 48 following substantially a revolution of the signal wheel I3, so that the rounds disk M wi l thereafter complete the final three-fourths of its revolution while the emergency switch ES is closed, and the contacts of assembly PC will act to formulate four signal rounds, the formulation of one of which will occur prior to the presentation of notch 35 to pawl 48 as just explained.

The emergency switching arrangement is eifective to permit proper transmittal of the signal under many malconditions of the line, a few of which will be pointed out to show the general utility of this switching arrangement. For example, referring to Fig. 21, let it be assumed that there has been a line break at the point X in the left-hand line section H between the boxes E and F, the emergency switch ES having been closed in the manner just described and the switch EW at the central station having been thrown into its alternate position (see Fig. 23) to connect third or ground line into the left-hand terminal of the battery CB while transferring the terminal of the line section H to th right-hand terminal of the battery. Under these conditions current may flow from the right-hand terminal of the battery through the lead B, conductors 52, 61, l3, l3, ll and ts, to the common return or ground from which the current passes to the left-hand terminal or minus s de of the battery. Accordingly as the switch PC is opened and, closed, the signal pulsations from the transmitter E are effective in actuating the signal-responsive device A, the arrangement of the three-point emergency switch ES p tting the pulsing into whichever one of the vo line connections may be closed, or,

both are closed, pulsing into them simultaneously. Obviously if the line break had occurred at point if (Fig. 21) rather than at point X, the hitter through its ground nilar to that just described, J rather than the device A being actuated.

As a. further example of possible faulty circuit conditions, let it be assumed for convenience of description that s circuit isdue to the joinder of point X with point Y of the line section B and that it is desired to signal from the intermediate box E and, furthermore, that the switch 5W has hen moved to its alternate position for emergency w or; (Fig. 23). When the switch ES closes under these conditions, one side of the line will be provided by the ground connection or common return CR, while the opposite line of the circuit loop will be provided by the conductors B and parallel.

If tiere is open circuit, for example, at the left of point AI on the line loop, and if the severed end of the line which extends to the right tou ward the be has been grounded, the boxes C, D and E may arm to control the receiving device A in the or. ary manner, without actuation of their emerge J switches in other words, performing as if the circuit was completed through its normal path, except in that the resultant signal will be manifested only by receiving device A. The boxes at the other side of the break, namely, boxes F and G, however, will require the closing their respective emergency switches ES to apply a ground connection, whereby the lcit l" nd circuit may be closed and sig ling effect may be manifested on the receiving devic If, for exanple, there should be circuit ope at l the points X and Y, the E would become isolated and in a hopeless condition. However, the remaining boxes G, F, D and C could st l operate after their emergency or grounding st ches had been automatically Under these conditions, if an attempt is made to operate its box the emergency switch will be the end of the first revolution of the signal wheel i3, and the movement of the arm permitted during the four succeeding rounds: of the s nal wheel will not cause response of either instrument A or J. Since, however, the clutch has remained closed, the rounds disk 15 in 58S- continually during the five revolutions of the shaft it and w eel iii, so that it is returned to a 13- tion where e notch 32 receives the stop arm it simultaneously stored in the spring Should the circuit be grounded either at X or at Y, while the central oiiice switch EW is normally positioned, such grounding will not alter the responsiveness of devices A and J to signals from any of the boxes, even if of low resistance. If, during the efiectiveness of such a low resistance ground of the exteinal circuit, the central oifice switch EW is positioned as shown in Fig. 23, signals from boxes to the right of such ground connection will be responded to by device A and those from boxes to the left of such ground will be responded to by device J; so that, if such ground connection developed at X, device A would respond to boxes 0, D and E and device J would respond to boxes F and CT.

Should low resistance ground connections develop at two or more points, or should a low resistance ground connection develop at one point and a break occur at another point, signals from any box or boxes situated in the circuit between such defects would fail to cause response of either device A or J. For example, should the circuit be grounded at X and at Y or broken at X and grounded at Y, or vice versa, any one of such conditions would render the devices A and J unresponsive to box E, irrespective of the positioning of central ofiice switch EW.

The arrangement of emergency switch ES permits shunting or excluding the magnet MM from the circuit so that a break in the magnet winding or in the immediate electric connections or the like does not prevent emergency working of the transmitter. Furthermore, this arrangement also is advantageous, since it requires relatively less current, since energization of the magnet is not required when working under emergency condi tions, thus permitting operation with a weak current.

Operation with optional circuit arrangement Fig. 22 shows a typical type of circuit which may be employed rather than that shown in Fig. 21, the differences in the circuits being in the arrangement of the central station portion CS. In the circuit arrangement shown in Fig. 22, which forms a portion of the subject matter of my copending application Serial No. 573,151, filed on even date herewith, the leads H and B correspond to those shown in Fig. 21 and may be connected to the signal boxes in exactly the same manner. The left-hand or primary winding of a transformer T may be connected to any suitable current source (not shown) which, for example, may be the commercial city lines, while the secondary winding of transformer T is connected across the input diagonal of a rectifier bridge or network RN. The latter comprises four rectifier units U, V, W and Z, so that onehalf wave of a current cycle may cause the upper terminal of the secondary winding of transformer T to be positive and the current may flow through rectifier unit W, receiving device A, lead B, serially connected boxes C, D, E, F and G, lead H, receiving device J, and rectifier V to the lower terminal of the secondary winding. During the next half cycle the lower terminal winding of transformer T may be positive, so that the current may flow outward from rectifier unit Z, thence over the same loop to return over rectifier unit U. Thus each half-cycle of the alternating current supply may be rectified in the network RN to provide a unidirectional pulsating current for the line loop and the devices therein rather than the direct current source CB of Fig. 21.

The central station CS, when having an arrangement such as shown in Fig. 22, requires no special switching or circuit changes for emergency working. For example, it may be assumed that an opening in the line section has occurred at a point X, such as shown in Fig. 21, and that subsequently the box E has been pulled. After one round of the signal wheel the emergency switch of the box is closed in the same manner as already described, so that during one-half cycle of the alternating current, current may flow from the lower terminal of transformer T through the rectifier unit Z, the serially connected device A, and stations in the line section B to the active signal initiating station, thence through the pulsing contact assembly PC of that station and its switch ES to the ground or return CR, whence the current will be received over the manifesting device R in the central station CS, thereupon passing to the upper terminal of the secondary winding of the transformer. During the next half cycle the direction of electromotive force will be such as to urge current flow toward the upper terminal of the transformer secondary winding T, from which parallel paths to the active station will be provided through manifesting device R and the ground or return CR, and through rectifier unit W, device A and line section B; but no return path will be provided from the active station to the lower terminal of the transformer secondary winding.

As another example of the emergency working of the arrangement shown in Fig. 22, in combination with boxes of the type disclosed herein, let it be assumed that the line loop sections B and H are connected by contact of points X and Y at either side of the transmitter E, thus shortcircuiting this transmitter. Under these conditions when the upper terminal of the transformer T is positive, current may flow therefrom through the rectifier W, line section B into the line section H and thence return through the rectifier unit V to the opposite terminal of the transformer, whi e current may also flow through the device R, emergency conductor CR, switch ES of box E, and thence through conductor H and unit V. When the lower terminal of the transformer T is positive current may flow through the unit Z, the line section B, to the contacting point of X and Y, a portion of the current then flowing through the leads (-32 and 6d, the contact member 13 and M, to the emergency switch ES and thence through the lead ii to the common return CR from which the device R may receive the signals, the current then passing to the upper or negative terminal of the transformer. It is thusevident that under these conditions the signal device R will be actuated by alternating current impulses received from the signal box E.

Obviously the wiring diagram shown in Fig. 22 is but a typical. example of a circuit arrangement which may be used advantageously with a signal box constructed in accordance with the present invention; in fact, it should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Signaling apparatus of the successive noninterference type comprising a first and a second pair of signaling contacts, three terminals, one of which is connected to a contact of one of said pairs and another of which is connected to a contact of the other of said pairs, an electromagnet connected between the remaining ones of 

